


Sink Like A Stone (I Won't Let You)

by Take_Me_To_My_Fragile_Dreams



Series: To Capture A Drowning Heart [1]
Category: Mortal Instruments Series - Cassandra Clare
Genre: Alec doesn't like rude people, Alec eats people, Alternate Universe, Claiming, Dirty Talk, Drowning, Fluff and Smut, M/M, Magic, Magnus is a pirate, Marking, Mating Rituals, Possessive Behavior, Siren!Alec and Pirate!Magnus sex, Underwater Blow Jobs, Underwater Sex, Water Sex, a pirate that's constantly getting into trouble, he's also snarky like whoa, if you haven't noticed already, it's me after all, of course there's some angst, slight angst, slight gore, what do you expect
Language: English
Status: Completed
Published: 2014-04-13
Updated: 2014-04-18
Packaged: 2018-01-19 05:41:27
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 12,067
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1457803
Author URL: https://archiveofourown.org/users/Take_Me_To_My_Fragile_Dreams/pseuds/Take_Me_To_My_Fragile_Dreams
Summary: <blockquote class="userstuff">
              <p>To capture a siren's heart is not something that many can boast of, but somewhere among the rescues and teasing banter it seems Magnus has managed to do just that.</p>
            </blockquote>





	1. Swimming With The Fishes

**Author's Note:**

  * For [TheShhTiger](https://archiveofourown.org/users/TheShhTiger/gifts).



> Sooooooooooooo this beauty is the first part of Sara’s birthday present which I managed to write in the matter of two days. ;_; Because I am a failure and never finished last years present, I found it necessary to make up for it (never underestimate the power of guilt. It can get you wonderful, terrible things.)  
> There are six chapters and I shall post one each day leading up to her birthday. All of them are already written and ready to go so you need not worry about my rather horrible tendency to never finish the things I start (I’M SORRY)  
> Now I just hope that I can finish the other part of her gift ;_;
> 
> Also
> 
> SURPRISE  
> YOU BETTER BE SURPRISED  
> YES I’M TALKING TO YOU SARA ;-;
> 
> *coughs*  
> Enjoy~

They were doing it again, causing a storm. He could hear their laughter echoing off of the rocks as they drew ships closer with their manipulated waves, nudging them towards the dangerous reef they resided in. Dangerous for humans that is, what with their gill-less bodies and soft unguarded skin. Alec never really understood why they tried to rule the seas when they couldn’t even _breathe_ in it. It seemed rather foolish on their part, like fish swimming in the middle of a group of sharks. They pretended to control that which they did not know, and were often killed for it.

Most of his people enjoyed making them suffer the consequences, liked to stir the waves enough to bring the ships close before emerging from the water to croon and beckon the sailors closer, laughing when their ships broke and shattered on the sharp rocks of their reef, bodies flailing helplessly in the water as their vessel sank, and yet still struggling to reach the owners of such sweet songs.

Sirens earned their legends, yes. They brought both fear and longing to men’s hearts, but they were not all evil. His sisters, the mermaids, regarded by most as gentle creatures were anything but. Alec had once witnessed a group of them tear apart a human that had had the misfortune of falling overboard, ripping him apart like sharks and giggling as blood stained the soft blue of the ocean. Humans knew not of what they played with in the sea, knew not of the death that they sometimes danced away from. They were such foolish creatures, that sometimes Alec understood his people, sometimes even joined in luring them to their deaths.

But that didn’t stop him from saving the drowning one with the green eyes.

* * *

It was not often that Alec saw humans betray their kind. He knew that it happened, had heard of a few instances where the men thrown overboard had either been saved or ripped apart depending on the creature that found him, and had understood in a way. Some day he could end up like that, chased out away from the safety of their reef by his people, deemed an outcast, for already they barely tolerated him and his strange ways.

Perhaps that played a part in his actions. Perhaps seeing the man struggle against bonds too tight to escape from as he fought to keep from sinking sent pity and understanding through the siren’s heart. Or perhaps it was the glimpse of his eyes, wide and oh so afraid, the bright color seeming at home in the ocean, that made Alec react. He didn’t know. All he knew was that he didn’t want to see this human drown, that he was going to save him from the cruel deaths his companions had planned for him.

Alec sliced through the water, a long tail of gleaming ebony and fishbelly white scales moving behind him and propelling him through the rather strong currents that tossed the human’s body back and forth, nearly smashing him into jagged rocks that would surely cause some damage. He didn’t have time to get him to the surface as he reached the tanned male, the last bubbles of oxygen were already escaping his lips and soon he would choke on water and drown.

Alec wasn’t going to let that happen.

He held the human gently, keeping him against his body in protection as he leaned down, pressing his mouth to the human’s and breathing out, redirecting oxygen through his lungs as he swam towards the surface. He felt a gasp as the male shuddered, eyes opening wide to meet Alec’s. They had barely broken the surface when he felt him go limp against him, his body sinking into unconsciousness.

The siren was almost tempted to let him go. How utterly rude.

* * *

When Magnus woke up, he expected… Well he expected not to wake up at all, to be honest. When one was thrown overboard with their limbs bound too tightly to swim, they tended to believe they were going to die. Instead he found himself resting on wet sand, the ocean lapping at his unbound legs and the sun boring into his eyes.

"Wha…?" He croaked, grimacing at the dryness of his mouth. He shifted, wincing slightly at the reminder of the bruises that were surely blooming over his skin from where the ropes had been tied tight enough to cut off circulation, pushing himself up onto his elbows and squinting at his surroundings. He was on an island of sorts, palm trees swaying in the gentle breeze just a few feet from where he laid, their shadows dancing over the sand and reaching for the hungry waves licking at his legs.

"You’re awake," a soft voice murmured, telling Magnus that he wasn’t alone after all. "I was starting to wonder if I’d have to drag you to the trees before you got sunstroke."

The pirate blinked, turning his head to peer into the waves, sucking in a startled breath when he saw the head bobbing above the foaming water a few feet away from him. The small fins protruding from the arch of the male’s ears gave his nature away if the flash of black and white scales didn’t. Magnus wasn’t one for being clique but he had to ask; "Who are you?"

The other male didn’t even blink (he wondered if he even _had_ to for that matter). "My name is Alexander, but you may call me Alec." A rather large wave curled over him, sending water into both their faces and Magnus found that when he blinked away the salt the siren looked as unfazed as ever, blinking wet lashes slowly, deliberately, as if to prove that he could have stared at the pirate for hours if need be. "And you?" He finally prompted when Magnus offered no more words. "What is your name?"

"Magnus," he answered, sitting up fully. "Magnus Bane."

"Well, Magnus," the siren smiled slowly, flashing sharp teeth. "You’ll be pleased to hear that I saved your sorry hide from drowning and quite possibly worse. You’re welcome."

Green eyes blinked.

_Oh. Oh well then._

There was a flick of long nearly translucent fins, a long tail made of ebony and pearl slicing through the water and sending water splashing, before Alec was gone, disappearing into deeper water.

It figured that he’d be rescued by the snarkiest siren alive. 


	2. I Don't Think Pirates Are Meant To Be Damsels

**Summary for the Chapter:**

> The second time they meet is an accident (sort of).  
> The second time they meet Magnus is close to dying (again).  
> The second time they meet the siren thinks that he might have saved the life of the stupidest human alive. (Though that doesn’t stop him from doing it again.)

"Do you have a death wish?" A familiar voice demanded from behind him. "Because it’s rude to go around being rescued only to chase after death. It would save me a lot of effort if you’d just tell people that ‘hey, I don’t want to be saved so you can just let me drown, okay?’ Then we could stop doing this and I could move on with my life."

Magnus blinked. "Been holding that in for long?"

The siren scoffed, flicking hair out of his face with a webbed hand. "Don’t flatter yourself, pirate. Otherwise I’ll leave you to my sisters."

"Sisters?" He questioned curiously, tilting his head to the side. "I didn’t know you had sisters."

"Well I do," Alec answered as if it were the most obvious thing in the world. "And they’re much more flesh hungry than I am so you’d better get down before they catch you."

"Down," Magnus repeated dubiously, eyeing the dark ocean. "You mean in the water?"

"Where else you frustratingly _thick_ headed human?"

The tanned male shifted down the jagged line of rocks he’d been walking across, scooting closer to the water hesitantly. The water was dark and uninviting except for the brief flashes of white that was the siren’s tail. "Are you sure-"

The sound of soft laughter and the occasional note of song hit his ears and Alec hissed, baring sharp teeth akin to a shark’s as his eyes flashed black. "Get down here _now_!"

Magnus obeyed if only because of the webbed hand that shot out to grasp his wrist, the blackened tips of Alec’s nails digging into his skin and yanking him towards the water. There was a disorienting moment when his head went under and the pirate thought that perhaps he should be worried about that and then Alec was winding an arm around his waist and swimming faster than Magnus thought possible, the ocean a blur of dark and light around them.

He was confused as to why he wasn’t drowning but decided that that could be questioned at a later date, eyes traveling over his rescuer instead of the nauseating sight that had become the world.

He hadn’t really had a chance to take in Alec the first time, having been disoriented and blinded by the sun (not to mention the other male’s abhorrence to sticking around). The only thing that was the same was those bright blue eyes, the color gleaming under the darker depths of the ocean.

His hair was longer than Magnus expected, the water pushing the black locks back behind his head in a soft streak that the pirate longed to touch. Thin white fins sprouted from the arch of his ears, the skin a translucent white that ended in a stripe of black. What looked like a piece of bone pierced the siren’s cartilage, the ends sharpened to tapered points that Magnus was sure could be used as a weapon if need be. Another earring dangled from his right earlobe, small tendrils of metal winding around the small multi-colored stone in a net of knots that made the pirate silently applaud the jeweler that had made the design. There were other pieces of jewelry he noticed—a silver band that curved around Alec’s upper arm, a belt that wound around his waist, sitting low on his hips, and another that wrapped around the scales just before his fins. Was it normal for sirens to have jewelry? Or was his just a magpie as well?

"If you’re done staring we’re far enough away to surface," Alec snapped, the sharp arch of his cheekbones dusted with pink. "Breathing air might be a little strange at first so brace yourself."

Magnus nodded silently, fighting a smile at the rather embarrassed look the siren had, raising his head to peer up at the quickly approaching light. The ocean was beautiful, if not deadly, the water turning a calm turquoise under the sunlight, piercing the darker waters faintly. The sudden brightness stung, making his eyes water as they broke the surface, heads bobbing above the gentle waves. It was strange, the pirate thought, taking in a shuddering breath. There was a pressure on his lungs, as if they were about to reject the oxygen and send him into a coughing fit before they seemed to settle, the weight in his throat disappearing with an exhale.

"I don’t suppose you could swim on your own for a while," Alec grumbled, tail waving beneath them. It wasn’t a suggestion.

"Contrary to your beliefs, I think I can handle treading water," he countered, pushing away from the siren reluctantly to swim on his own, arms and legs working to keep him above water. "How could I breathe underwater anyways?"

"Magic," the siren answered flatly, circling around the human, fins slicing through the water. If Magnus didn’t know that Alec wouldn’t have saved him just to kill him he might have been afraid.

"I could have never guessed." He deadpanned, rolling his eyes and flicking wet hair out of his face. "What kind of magic genius?"

"Siren magic," Alec answered, apparently unable to do anything but state the obvious. "God, you really are thick aren’t you?"

Magnus scoffed, eyes narrowing at the siren. "I’m starting to think you rescue endangered lives just so that you can insult their intelligence."

"You can’t insult something that isn’t there."

_Well. At least he hadn’t gotten a boring one._ And if he had to be honest he was quite enjoying their banter, it was rare to find someone who you could talk like this with without having to come to blows and swords. Most people he kept company with were short tempered and well, thick as the siren would say.

"I’m starting to think that perhaps I should just eat you myself and save anyone the trouble of rescuing your apparently suicidal being," Alec continued, rather predatory eyes peering out at the pirate from the water.

Magnus couldn’t help the shiver that ran down his spine in warning. "But you won’t." He stated with false confidence. "Then saving me both times would be meaningless and a waste of time."

The siren smiled, slow and sharp and there was a storm that could sink that greatest of ships in his eyes. "Perhaps that’s how I lure my prey in," he crooned, slipping behind the pirate.

Magnus sucked in a sharp breath when fins brushed his legs, slippery smooth.

"You came looking for me, didn’t you?" He breathed, voice at the human’s ear, clawed hands resting on slender hips. "You made your way towards my home like the foolish creature that you are. Why?" Alec questioned, dragging his hands up under his loose shirt and stopping only once they rested on Magnus’ chest, right above his pounding heart. "Tell me why I shouldn’t just rip your heart out and devour it for myself when you’ve come and delivered yourself to my door, a delicious meal all for me."

The pirate’s breathing was ragged, limbs still as he rested against the siren’s chest, his legs brushing against the smooth expanse of Alec’s tail, sending disconcerted shivers through his body. They bobbed gently in the water, a peaceful scene in the large expanse of ocean with the sun smiling down at them. Magnus closed his eyes. "Because you don’t want to."

There was silence after his whispered words, broken only by the soft sounds of water lapping at water, waves meeting each other in a wet embrace.

"No," Alec finally murmured, nodding slightly. His sigh brushed against the skin of Magnus’ neck. "I don’t." His hands slid away from the human’s chest, claws gentle against fragile flesh. "I don’t want to kill you, you insufferably suicidal idiot pirate,"

"Not even to eat my heart?" Magnus teased softly, body relaxing at that as he turned to peer back at the other male.

The siren smiled slightly. "No," he agreed. "Not even then."

* * *

"Try not to die anytime soon, alright?" Alec murmured, watching the human stretch slowly on the sand. “It’d be a pain.”

Magnus flashed a smile as he rolled his shoulders, getting used to being on land after almost a day’s worth of being in water. "Why _ever_ would I do that? Especially when I get such a handsome rescuer."

The siren flushed, sinking lower into the water until only his eyes peeked out of the waves. His tail splashed behind him as if in answer.

The pirate grinned.

"Next time I’ll just let you drown," Alec finally grumbled, turning away from the beach as if to go.

"Wait!" Magnus called, darting towards the waves as if to pull the siren back. "Do you really have to disappear like last time? And after I came so far to find you?"

"You nearly got yourself eaten," he answered flatly, looking unimpressed. "Why should I reward that?"

"Because I’ll only do it again if you don’t?" Magnus answered cheekily.

Alec looked as if he was contemplating a world without idiotic humans.

"Please?" He added, expression turning sincere. "I really would like to see you again."

There was a pause, the siren throwing the pirate a rather flustered and bewildered look. "Just see?" Alec finally managed, raising an eyebrow. "I’m not an animal in a cage, Bane.”

“I should hope not,” he snorted. “You don’t belong in a cage. Besides--then I would be the one doing the rescuing.”

The blue eyed male smiled slightly at that, eyes warming to a light shade of blue. “I will return tomorrow when the sun begins to set. Don’t be late.”

“Wouldn’t dream of it,” Magnus murmured, watching the flash of black and white scales before the siren was gone.


	3. Don't Cage What You Can't Tame

**Summary for the Chapter:**

> It was hard finding time to meet with the siren when he couldn’t resist the temptation of the ocean, joining the Idris crew and traveling through the seas. It was hard to keep Alec a secret when most of the time their meetings were held out at sea when the rest of the crew was asleep, but they managed. No matter what the blue eyed male always came on time, slinking through the dark waters and risking everything just to talk to the pirate. It was stupid (and touchingly trusting) but they did it.
> 
> Which was why Magnus knew something was wrong when Alec didn’t show up.

**Notes for the Chapter:**

> An angry Alec does not bode well for any humans near by, by warned of slight gore.  
> Also, Sebastian is in this chapter. Do not get attached.

The town near their island was a rather large and boisterous one. The humans were akin to any others in the world and there were, of course, the difference of classes. There were the drunkards, the prostitutes, the pirates, the normal man who did anything from blacksmithing to baking, the housewives and the everyday families. They were contained to the lower portion of land, closest to the ocean while the rich settled high up on the cliffs, their large houses gleaming under the sun.

That was where Magnus found himself going.

He’d heard rumors after asking around, about a rare creature who’d been caught just off the bay, trapped in fishing nets and unable to escape. They’d taken the poor thing up to the nobles, one woman had said, looking regretful. It had such pretty scales too…

So, the pirate found himself riding up into the cliffs, paying for a horse with half of what he’d earned while out at sea and quickly making his way to where he hoped his siren was being held.

(He silently prayed that he wasn’t too late.)

* * *

Alec stared mutinously at the glass surrounding him, baring his teeth at the empty room, the small black spines on his back standing on end as his claws glistened with poison. He had been foolish, getting caught in those nets, not paying attention as he waited for nightfall to find Magnus and now he was stuck in this insufferable prison.

He may be trapped, this far from the ocean with no way to get back, but he would rip apart any who dared to touch him; he would bite off their smug looks and eat their gloating eyes; he would drown them in their blood and laugh as he sang them to hell; would tear out their hearts and make them watch as he ate it, would-

“Alec,” a familiar voice whispered, sending the siren spinning towards the window across from his prison. “Darling, are you in there?”

“Magnus!” He breathed, relief surging through his veins as his tail flicked anxiously. “I’m here.”

A lithe form slipped through the polished wooden doors, sending a sliver of moonlight into the dark room as he made his way to the siren, green eyes gazing up at the male who he’d come to call a friend. “I once told you that you should never be kept in a cage,” Magnus murmured, touching his fingers to the glass.

“And do you still believe that?” Alec whispered, feeling a sliver of fear. Perhaps his trust had been misplaced… Humans could be so greedy…

The pirate smiled, eyes running over the ladder connected to the side of the large tank. “Yes. And I believe,” he continued, climbing up the rungs to examine the bars that made up the top of Alec’s prison. “that I also said that I would end up rescuing you.”

“Magnus wait,” he whispered urgently, surfacing to peer up at the pirate. “if you take it off it’ll make noise and you’ll be caught.”

“That’s fine,” Magnus dismissed, brows furrowing as he wrapped his hands around the thick metal, yanking it up and sending a horrible shriek through the air.

Alec cringed, watching as the metal was tossed aside, tanned hands reaching towards the water.

“We have to hurry,” Magnus hissed, catching the sounds of stirring. “We need to get out of here.”

The siren nodded, reaching up towards the human’s hands and banishing the poison coating his claws back into his skin.

“I’m afraid you won’t be going anywhere, _pirate_.” A voice sneered, light flooding the room as several men stalked into the room. “Seize him.”

Magnus growled, hand moving to his sword a moment too late, two pairs of hands grabbing his shoulders roughly and yanking him down from the ladder, forcing him over to the man who’d spoken, a hard shove sending him to his knees.

“I don’t take kindly to people trying to steal my things,” The man murmured, voice arrogant.

Alec wanted to rip him apart. This stupid, ignorant, _worthless_ human had had him caged, had tried to take away his treasures, had taken him away from the ocean and now was threatening his pirate. The siren hissed.

Sebastian smiled. “He is quite something, isn’t he?” He questioned, eyes roving over the siren. “I can understand why you’d want to take him but that doesn’t mean I’m going to let you off easily. No, I need to make it clear to you ingrates that what’s in this house is off limits.” Cold black eyes moved from Alec to the man kneeling at his feet with a cruel smile. “Since you wanted into that tank so much, I’ll give you your wish, pirate.” He waved a hand. “Put him in the tank. I’m sure my pet is getting hungry.”

The two males moved obediently, dragging the struggling male back to the tank and forcing him up the ladder. Magnus eyed the water below, kicking out at the men and crying out when a fist hit his stomach, stealing the breath from his lungs.

Alec had had enough. He shifted, surfacing with a slow flick of his tail, eyes catching the pirate’s as a slow smile spread over his lips. A soft croon left his mouth, a melody beginning to surface in the back of his throat as he reached up, hands cradling Magnus’ face as he drew him closer. He waved above water, humming gently as he drew the human away from the others, slowly backing away from the ladder and dragging Magnus with him until the pirate was sliding into the water with a small splash, his lips stolen.

There had been few times that they had done this, but it always made Alec hungry for more, tongue lapping and teeth nipping at Magnus’ mouth as they shared breath. He wound his magic around the pirate’s lungs, weaving the simple spell that would allow the man to breathe in the salt water before parting from his lips, fingers running through soft locks. Glazed green eyes peered back at him, his expression dazed as Alec hummed the last of his song, a small smile gracing his lips as he laid the pirate down on the sand-lined bottom of his cage, making sure he was comfortable before turning towards the three men watching.

It took all of seconds for the siren’s expression to change. With an angry shriek he surfaced, catching one of the guards that had wandered closer to the glass during his song with a hand, yanking him up by his air and burying his teeth in the soft skin of his throat, ripping and tearing at the flesh with a cruel laugh at the male’s pathetic screams, the body falling with a useless thump when he let go.

He smiled, brilliant and wide at the second, bits of flesh clinging to his teeth and blood dripping from his mouth. Alec crooked a finger, a seductive hum emerging from his throat. “Come,” it was not a suggestion.

The man obeyed.

He was easy, a hand through his throat and he went down with a helpless gurgle, choking on his own blood as he clutched at the torn skin, eyes wide and lips moving uselessly.

Alec laughed as he pulled himself from the tank, sliding down the ladder as his eyes zeroed in on the now pale Sebastian. The man backed away as he dragged himself forward with clawed hands, poison sizzling as it dripped from his nails, burning holes into the tiled floor as he hissed. “A treasure am I?” He mocked, backing the once powerful man into a corner. “Your pet?” His tail slammed into the floor, shattering the material. “I belong to _no one_.”

The other men had been discarded, given quick and rather painless deaths, but this one, Alec bared his teeth, eyes impossibly cruel. This one would _suffer_.

Screams rang long through the night.

* * *

“Magnus,” Alec murmured, cradling the human’s head in his lap, webbed hands running through wet locks. “Wake up, my pirate.”

The male groaned, eyes blinking slowly as he shifted, the dazed look on his face melting away. He peered up at the siren, confusion filling his eyes before he jerked upright with a gasp, eyes wide as he took in the mess around him. They were sitting in a pool of spilt water, broken glass and blood, the glass of Alec’s tank broken and caved into itself, the remains of three bodies littering the now dark room.

“The blood’s not…?”

Alec’s head shook. “It’s not mine,”

“Good,” Magnus murmured, turning away from the dead without questions. “We should get out of here then.”

The siren nodded, gazing up at the pirate as he stood, the last of his song wearing off of the human.

“Come on,” he slid an arm under Alec’s tail, lifting him into his arms and holding the siren against his chest, the long expanse of his tail just barely brushing the ground. “Let’s get you back to the ocean.”

Alec nodded, wrapping an arm around the pirate’s neck as he rested against Magnus’ chest. “Thank you,” he murmured quietly.

The human smiled ruefully. “I didn’t really do anything. It seems you pretty much saved yourself.”

Alec shook his head, frowning slightly. “I couldn’t get back without you. Everything would be worthless then.”

Magnus cast one last look at the room, tightening his hold on the male in his arms. It wasn’t until they were riding towards the bay, the siren resting against his chest as the horse moved that he finally answered, his words quiet and almost swallowed by the wind. “You’re welcome.”


	4. Rarer Than The Brightest Of Colors

**Summary for the Chapter:**

> Magnus had never really touched Alec’s tail before. Never really even gazed at it for long periods of time really. As the siren had said, he wasn’t an animal locked in a cage for others to gaze at. He was a person (a rather dangerous one) who didn’t enjoy being stared at for that matter.  
> So the times that he was allowed to look, to touch even, were cherished and taken advantage of in full.

**Notes for the Chapter:**

> Sex. That's all I can say.

The scales of Alec’s tail were rather cold to the touch, their surface slippery smooth until they merged with the small downy feathers at the siren’s waist. The feathers were nearly invisible unless you were looking, the pale white blending with Alec’s skin. Magnus wouldn’t have even known that they were there if he hadn’t touched them while examining the belt that wound around the siren’s waist in loops of metal and jewels (it turned out that all sirens had a tendency to collect ‘treasures’). They were soft, akin to a seal’s pelt when wet and rather sensitive. Pulling on them was like pulling a handful of hair out, something that Magnus apologized profusely for after accidently doing just that.

Smooth black spines arched out from Alec’s hips, webbed together in a translucent white that billowed slightly in the water. Another pair--smaller but identical--sprouted just below the cuff that wound around the end of the male’s tail where long fins met scales. Small swirls of black dusted Alec’s upper body, winding around his wrists, resting under the gills below his ears, and spotting around the spines of his back.

He was beautiful, a rare sight to behold and Magnus couldn’t help but stare when he could.

“Why do you keep looking at me like that?” Alec mumbled, squirming slightly in the shallow water of the bay as he ducked his head, shivering as Magnus’ hand resumed petting his tail.

“Like what?” The pirate teased, scratching gently at soft feathers.

“You- you know what!” He grumbled, a soft pleased sound escaping his throat.

Magnus chuckled, leaning his forehead against the siren’s as he stole a kiss. “Because you’re beautiful.”

Pale cheeks flushed at that, blue eyes dropping to webbed hands sheepishly. “My brothers and sisters are far more so, I can assure you.”

“I doubt it,” he dismissed, twining his fingers with the siren’s.

“It’s true!” Alec protested, sharp teeth biting into his lip. “They have much prettier scales in as many colors as you can imagine.”

Magnus seemed to consider this. “Purple?”

“Yes,” he nodded.

“Blue?”

“Of course.”

“Orange?”

“Yes, I did say that-”

“Red?”

“Magnus,” Alec growled, tail flicking sharply against the water in frustration. “I said all colors.”

“Doesn’t matter.” He shrugged. “Bright colors can be found anywhere. You, however, are covered in white and black pearls and that is far rarer in my opinion.”

Red stained pale white cheeks and the siren looked away. “Flattery will get you nowhere with me, pirate.”

“I know,” Magnus smiled, brushing a strand of hair out of blue eyes. “Have you ever considered that perhaps I’m merely complimenting you because it is the truth and I wish you to know it?”

Alec flicked a small splash of water towards the pirate, peering up at him. “Is that one of your human customs?”

“I suppose so.”

He seemed to consider that for a moment, nodding resolutely. “Then I find you beautiful as well.” The siren answered honestly before turning back to the water, stretching out onto his back luxuriously.

The pirate blinked in surprise at that, before a slow smile took his mouth. “I’m glad.”

* * *

“Is there anything else you can do with magic besides make humans able to breathe underwater?” Magnus asked curiously, smiling as he held a hand out, laughing softly when a small seahorse swam around it eagerly.

Alec was silent for a moment as he watched the human, tilting his head to the side. “I can control the weather to an extent. If there are enough of us we can bring great storms and sink the largest of ships or flood the most protected of lands. There is magic in our song as well, as you’ve experienced and the water moves at our will. I can…” He hesitated, gaze uncertain. “If need be I can also shed my tail for a pair of legs instead, though it will leave me quite weak for a while.”

Magnus blinked, turning to the siren in surprise. “Would you be able to change back?”

“Yes,” he nodded. “Though not for a few days or so, depending on the amount of power it would take. It’s meant only as a last resort, when we’re at our most desperate. Or for… mating purposes.”

The pirate couldn’t hold back a chuckle at the flustered look on the other male’s face, cheeks flushed and body squirming in the water. “You don’t mate with your own kind?”

“It’s more up to preference,” Alec mumbled, looking away. “But even when mating with one another most prefer to do it on land, where it’s safe from any dangers that could interrupt the process. Besides, mating while underwater can be… hard.”

“I’d imagine so,” Magnus agreed, nodding slightly.

“Oh god,” he groaned, hiding his face in his hands. “you’re imagining it aren’t you? Have you humans no decency?”

“Some do,” the pirate answered, a slow smirk tugging at his lips. “but it makes things so… _boring_.”

* * *

“Alec,” Magnus murmured, running his hand through black locks. “I should probably go soon, it’s getting dark and the ship sets sail tomorrow.”

The siren frowned, turning to gaze up at the pirate from his place on the other male’s lap, tail draping over Magnus’ thighs. “I guess,” he mumbled, eyes turning a light gray.

“Hey,” Magnus murmured, crooking a finger under his chin and tipping his head up. “I’ll see you every day at nightfall, remember?” He smiled, bumping noses teasingly. “After last time I want to keep you close.”

“You treat me like your pet dolphin,” Alec grumbled, relaxing against the pirate’s chest as he tipped his head up, closing the distance between their mouths.

“Nonsense,” he dismissed breathlessly, lips parting under the siren’s silent urgings, a low moan leaving his mouth when the other male sucked his bottom lip into his mouth. “If anything you’re a shark.”

Alec snorted at that, hands sliding down the pirate’s chest, nails dragging gently as he reddened Magnus’ mouth. “Is that meant to be a compliment?” He murmured, trailing his lips down the human’s throat to mouth at the delicate skin there, teeth dragging hard enough to nearly break skin. “Sharks are rather dumb beasts, focused only on their kill.”

“I don’t know about the first part,” Magnus panted, hands sliding down over Alec’s hips to stroke his scales. “But you certainly focus on your kills.”

He smiled at that, a slow predatory smile as he sucked at the abused skin, trailing bite marks down his human’s neck. “Believe me, pirate,” Alec crooned, fingers curling into the tops of Magnus’ pants. “you have seen nothing of focus. If I wanted to, I could bring you to my home and keep you for _days_ , writhing in a mix of pleasured pain that only I could give you--helpless to do anything but be devoured.”

A soft desperate sound left his lips at that, hips arching up into the siren’s touch. “Oh?”

“Mm,” Alec chuckled, palming the growing heat beneath his hand as he stole one last kiss before he was sliding back into the ocean, eyes twinkling. “Run along, my pirate. As you said, you should rest.”

Magnus blinked dazedly, body thrumming with desire for the beautiful creature bobbing just inches away from his feet. “You could put even the worst of teases to shame,” he grumbled, standing on shaky legs.

“I guess I’ll just have to fix that later than, hmm?”

* * *

“Magnus!” Alec called softly, peering up at the deck of the large ship, bobbing among the waves as he held on to the slick wood.

“I’m here,” the pirate answered softly, emerging from the shadows to lean out over the railing, gazing down at the siren.

“Come down,” he smiled, eyes beckoning the human as he let go off the ship, darting under the water with a soft flick of his tail, surfacing once more to add: “And take off your clothes.”

Magnus cursed softly, eyes scanning the deck for any occupants. Other than a few men at their posts there were none, making it rather easy for the pirate to slip towards the ladder. He hid his clothes behind one of the canons, making sure that they would be out of sight should anyone pass by unexpectedly before slipping over the side of the ship quickly, climbing down the ladder with a speed born of practice.

The water was dark, glittering with the reflection of stars and mysterious enough to make anyone uneasy of just what might come out of the water. The waves were calm, lapping gently at the sides of the ship in a melody that Magnus knew well, and had come to love. “Alec?” He called softly, shivering as he slipped into the water, turning to put his back to the ship while keeping a hand on the rope of the ladder.

He stiffened when he felt something brush his legs, the touch of scales familiar though made slightly uneasy by the darkness. A pair of hands slid up his legs, following the slope of his calves up to the bends of his knee before slipping upwards further still to push his thighs apart slightly. “Alec, darling,” Magnus breathed, peering into the water in an effort to see the siren. “what are you doing?”

The male was silent, making no effort to surface and explain just _what_ it was he was trying to do though Magnus had a pretty good (and hopeful) idea. Something rough flicked against the muscles of his inner thigh and it took a moment for the pirate to realize that it was the siren’s tongue, a quiet moan spilling from his lips when he proceeded to suction his mouth to that same spot, sucking a bruise into tanned flesh. Alec had a thing for marking, Magnus had realized. He liked to create as many signs of their time together as he could, covering the pirate’s skin in bruises and bitemarks. It seemed more of a territorial thing (sirens were extremely possessive and selfish when it came to their treasures) than anything else, though it wasn’t like he was complaining. He enjoyed being thoroughly marked and claimed as the blue eyed male’s. After all, he had no intentions of trying to bed someone else.

“Alexander…” Magnus breathed, head tipping back as he tightened his grip on the ladder. He shivered as that sinful mouth moved higher, leaving a trail of bruises from the skin just above his knee to the skin of his groin, sending heat licking down his spine. He groaned when the siren bypassed his arousal, moving to create the same pattern on the other leg as webbed hands held his legs open. If Magnus peered down into the water he could almost swear that he could see a flash of white.

“Alec, please,” He finally moaned, arching his hips up when the other male had come back to his upper thigh, the last bruise just inches away from where he ached for that mouth. He could imagine that familiar predatory look on his lover’s face, his eyes unblinking as he zeroed in on his prey, mouth parted hungrily and eyes flashing black. The image made the pirate all the more desperate, a soft whine leaving his lips as he ground his hips up in the water, struggling to get closer to that allusive mouth. “Alec…”

A sharp bite to the thin skin of his hip had him stilling, the message clear. _Behave_.

Magnus hated behaving. “Alec…” He tried once more, voice pleading as he stared down into the water imploringly. He might not be able to see the siren but he knew damn well that Alec could see him.

All was still for a moment, nothing but the gentle sound of water filling the night and then Magnus was crying out, back arching as he tried desperately to keep quiet, that talented mouth moving over his arousal and taking him deep. The siren took him as hungrily as he devoured prey (and Magnus had been witness to that rather… gory sight a few times) licking and sucking greedily at aching flesh as his nails dug into the pirate’s thighs, pushing them apart and keeping the human still. Alec was careful with his teeth and for that Magnus was grateful, though he had to admit that the slight brush of the dangerous tools had him shuddering with arousal, the danger making it all the better.

“Al- _ah!_ -Alec-” Magnus panted, raising a hand to bite down on the back of it in an effort to quiet the noises escaping his mouth.

The siren hummed around him in answer, a low seductive sound that sent chills down his spine and made his toes curl, body _burning_ under the spell of his song as Magnus let out a long tirade of curses, voice breathless and trembling. “ _Fuck_! Alexander you-- _ohh, god_ \--you have--have to--”

Magnus gasped as those familiar hands tugged his legs over strong shoulders, a sharp flick of the siren’s tail finally lifting his upper body out of the water along with the pirate’s hips. He moaned at the sight of his arousal sliding out from between Alec’s lips, a tongue flicking against them as if the siren wanted to savor the taste of him.

“Alec-”

“I want to take you,” he interrupted, voice low and hoarse. His eyes were a brilliant blaze of color, gleaming in the dark and slicing through Magnus’ soul as a webbed hand wrapped around his weeping cock. “I want to claim you right here, make you scream and beg and wake up those humans you hang around with all day and show them just _who_ you belong too.”

His words thrummed with power, sending sparks of pleasure through Magnus’ senses as he shuddered uncontrollably. _He wanted that_ , he found, a desperate moan leaving his lips as he clutched at the ladder behind him, shoulders dipping lower into the water as the siren held his hips up, an offering all for him. _God did he want that_. He wanted to be claimed, wanted to be surrounded by Alec, wanted to be spread out and fucked and taken over. “Please-” he gasped, eyes rolling into the back of his head.

“Do you want that, Magnus?” Alec purred, dipping his head to mouth at the base of his arousal, a finger swiping over the puckered skin behind his balls. “I could give you so much, you have no idea…”

The pirate let out a strangled cry, body lurching as if to get away before he crashed back down into the water with a sharp splash, sending salt water flying. “A-alec-” He was so close, his body shivering with it as his muscles tensed, pleasure spreading right down to his very core.

The siren hummed, letting out another string of that seductive song, words that Magnus couldn’t understand drowning his senses in a pleasure that he willingly submitted to. “Cum for me, my pirate, let me see you come undone.”

He didn’t think he could _be_ any further undone, something that Alec proved wrong as he arched sharply. A loud cry that Magnus was hopeless to muffle escaped parted lips as he was engulfed in that mouth once more, the siren taking all he had to offer as his body spent itself, shivering in the waves. His legs kicked under Alec’s firm grip, the pleasure exploding through his senses and wrecking his vision, turning muscles to trembling messes and melting bones. He was helpless under his lover, helpless in a way that he couldn’t get enough of, and that made it all the better.

Magnus nearly cried out in loss when Alec moved his mouth away, letting his legs slip from his shoulders and cradling him close. “Shh, my love,” he soothed, pressing a kiss to the human’s forehead, hands stroking over his lover’s back. “I’ve got you.”

“I love you,” Magnus found himself gasping, chest tight with the terrible and joyful truth.

Alec smiled slowly, stealing his mouth. “And I love you.”

**Notes for the Chapter:**

> *whispers* I'm working on my dialect during sex to try and make it flow and sound better so tell me how it went?


	5. Of Blood and Shed Scales

**Summary for the Chapter:**

> They preferred to stay in the present rather than the past. Sure Alec liked to know about Magnus’ human life and vice versa, but they never really delved deeper into the matter than was necessary. The past was a storm just waiting to sink them, waves angry and skies crying.
> 
> Eventually though, they had to face it.

**Notes for the Chapter:**

> More sex *coughs*

“Do you have any siblings?” Alec questioned curiously, tilting his head to the side as he peered up at the pirate, arms resting on the rock Magnus sat on.

“No,” he shook his head, running a hand through the siren’s hair.

“What about your parents?” Alec prompted curiously, leaning into the touch.

Magnus frowned, stiffening slightly before he resumed his attentions, scratching lightly at the scales behind Alec’s ear, something that had the siren moaning in appreciation. “They’re gone.”

“What do you mean?”

“I… don’t think you want to hear it.” The pirate answered, shaking his head. His lover was incredibly protective at times, and something like his childhood story would not bode well.

“Please?” He requested, eyes pleading as he caught Magnus’ hand, nuzzling into his wrist.

The other male sighed, smiling slightly at his lover’s actions before turning his gaze to the ocean. “My mother was raped early on in her marriage. From what I managed to piece together she kept it a secret and hoped that when she got pregnant it was because of her husband and not her assaulter. However, when I came out looking nothing like him and little like her, it didn’t bode well.” He shrugged, eyes darkening as he ran his thumb over the fins of Alec’s ear. “He hated me, wanted me gone. Sometimes he beat me, or locked me up with no food and she let him, too scared for herself. She couldn’t look at me, I think I reminded her too much of my father and eventually she just… Stopped trying. She wasted away and one day she went to the beach and never came back.”

Alec frowned, raising himself to wind an arm around Magnus’ waist, tugging him closer. “What happened after that?” He questioned softly, resting his head on his lover’s thigh.

“A week or so later her body washed up. After that her husband didn’t hold back. He came close to killing me a couple of times--I still have some of the scars. When I turned 15 I got out as fast as I could and joined a crew to get far away from that place.” Magnus shrugged, smiling faintly. “I’ve never gone back since.”

They were silent for a few moments before Alec finally spoke, curling his fingers around the pirate’s. “You are safe now,” he reassured, finding little sense in apologies. “no one will harm you like that again.”

A small smile--a genuine one this time--crossed Magnus’ face at that as he leaned down, brushing a kiss to his lover’s forehead. “Thank you.”

* * *

“I’m going to have to leave this place soon,” Alec murmured one night, body curled into his lover’s as they laid among the warm sand.

“What?” Magnus blinked. “Why?”

“My sisters are starting to get suspicious about where I’ve been going. They’ve been tolerating me up until now but I can only push them too far. I don’t want it to resort to a fight.”

“Could you win if that happened?”

Alec was silent for a moment, staring at the hand on Magnus’ chest, just above his heart, before he shook his head. “Perhaps,”

The pirate wasn’t convinced.

* * *

Blood. That was the first thing Magnus registered as he came upon their meeting place. So much blood. It stained the rocks, the water dragging the crimson back and forth over the sand and doing little to get rid of it. There were deep grooves in the stone, as if someone had taken great handfuls in an effort to pull themself up. Or to reach something else.

“Alec?” Magnus called, voice frantic as he darted through the sand, climbing up onto ragged rocks. There were too many, some taller than him and he couldn’t see his lover anywhere. He followed the trail of blood, searching desperately for answers. He came across something that gleamed under the sun and with a sinking heart he knelt down, picking up the small black scale, no bigger than the pad of his finger. He shoved it into his pocket, increasing his speed as he rounded the corner of a rather large rock taller than himself, sucking in a breath at what he saw.

Alec was curled into himself, body dusted with sand and crusted with blood. His hair was matted and tangled around his head, eyes closed and breathing shallow, his tail gone. The beautiful black and white scales were gone from his body and replaced with pale white skin, his fins shed for a pair of feet instead.

“Alec!” Magnus cried, darting forward to fall to his knees next to the siren, hands moving restlessly over his lover. There were deep cuts on his neck and chest, and his legs were covered in wounds. He recalled the grooves he’d seen, dug into the rocks and shuddered. They were claw marks, meant to rip away flesh and immobilize. He wondered how long Alec had endured the torment, how much effort it had taken him to drag himself out of the water, grabbing desperately at the rocks as he tried to get away, the danger great enough that he had shed his tail, crawling as far away as he could before collapsing.

The pirate cursed himself for not coming sooner as he shed his shirt, wrapping it around his lover’s body and lifting him into his arms. “You’re safe,” he promised when the siren let out a soft whimper. “I’ve got you.”

Magnus trudged up the beach, careful to stay away from the water lest any of Alec’s ‘sisters’ still be near by, for he had no doubt that they had done this. The siren had said himself that it might soon come to a fight, and it was clear just who had won.

The pirate cursed himself once more.

* * *

Alec groaned, shifting restlessly as Magnus treated his wounds, bandaging the various cuts and bitemarks that marked his slowly healing body. He drifted in and out of consciousness, exhaustion from the fight and the change to human form keeping him from staying awake for more than a few moments at a time; though every time that he opened his eyes, Magnus was right there, caring for his wounded body and soothing him back to sleep.

Not for the first time, the siren thought that his mate was perfect.

* * *

“...nus…”

Magnus stirred, opening tired eyes to blink wearily at the room, his head pillowed on his arms.

“...’agnus…”

The pirate shot up, sleep deserting him as he scrambled up to Alec’s head, curling his fingers around the siren’s searching hand. “Shhh, I’m right here, love.” He soothed, running a hand through his lover’s hair. He’d done his best to wash it while Alec was unconscious, combing the sand and rock out from his shoulder-length locks and cleaning away the blood.

“Hurts,” Alec mumbled, grimacing as he shifted onto his side, skin tugging at his wounds and sending a wave of pain through his body in protest.

“I know,” Magnus murmured, pressing a kiss to the back of his hand. “it’ll get better soon.”

“If I hadn’t had to change it would be better now,” the siren hissed in frustration, frowning down at his bandaged legs.

“I know,” he repeated, running a soothing hand down his lover’s side.

Alec calmed at that, relaxing into the bed as he watched Magnus, eyes on his face. “I was worried I wouldn’t see you again.” He finally admitted, reaching down to catch the human’s hand with his own.

“What happened?” Magnus murmured, squeezing his hand gently. “Why did they do this to you?”

The siren grimaced, biting his lip. “One of them saw me with you a few nights ago. They didn’t like the way that I was constantly returning to the same human without ‘playing’ with you.”

“Playing?”

“Calling you into the water to drown, eating your flesh, things like that.” He explained, making a face. “They’ve always been jealous of my treasures.”

“Your treasure am I?” Magnus teased, leaning down to rest his forehead against the siren’s.

Alec smiled softly, squeezing his hand. “The only one that matters.”

* * *

“Alec, what are you doing?” Magnus questioned worriedly, rushing to the bed. “I don’t think that you should-”

“It’s fine,” he dismissed, beginning to unwind the dirty bandages on his legs. “They should be mostly healed anyways.”

The pirate frowned but made no move to stop him, watching as pale skin was revealed, small lacerations littering his skin. “It’s only been two days,” Magnus breathed in surprise, touching his lover’s thigh.

“They would have been healed fully if I hadn’t exhausted so much power,” Alec grimaced, beginning on the ones on his stomach. “I need to bathe.”

“You can take a bath.” Magnus offered, casting a gaze towards the tub in the corner. “This is one of the nicer rooms so we won’t have to lug buckets up the stairs.”

Alec cast him a confused glance. “Why would you need to do that?”

“Not all of us have the luxury of being able to control water,” Magnus chuckled, ruffling the other male’s hair. “If we want it--especially heated--then we have to work for it.”

“Oh,” he mumbled, eyeing the tub dubiously.

“Come on,” the pirate smiled, tugging him up and helping to support his shaky legs. “I’ll show you how it works.”

* * *

“Legs are so strange,” Alec murmured, wiggling his toes as he peered down at them, wet hair falling around his face.

“How so?” Magnus questioned, chuckling softly as he watched his lover.

“They just are.” The siren answered simply, raising his eyes to meet amused greens.

“Very descriptive, love.” He nodded, raising an eyebrow teasingly. “Really, couldn’t have said it better myself.”

Alec huffed, tossing a pillow at him. “It’s hard to explain to someone who’s never had a tail. Legs are so… separate and exposed.”

Magnus smirked, running a hand down his thigh. “Oh believe me, darling, I’ve noticed.”

He flushed, ducking his head to bury his face in his knees sheepishly, squirming on the bed. “I don’t like clothes,” He finally muttered, looking away. “They’re scratchy and constricting.”

“I wasn’t complaining.” The pirate hummed, tugging the siren closer. “On the contrary, I’m quite enjoying it.”

“Because you want to mate?” Alec questioned, biting his lip as he peered up at him.

Magnus blinked. “I suppose you could put it that way, yes. Though that’s not the only reason. You’re beautiful after all,” he smiled, tucking a strand of hair behind his lover’s ear. “I quite enjoy looking at you. And not just because I want to jump your bones either.”

“We could…” The siren began hesitantly, looking unsure as he fidgeted. “We could try it. Mating I mean. We’ve never really… I mean, I’ve never but I know how… how it works…”

Magnus chuckled, pressing a kiss to his cheek. “Maybe when you’ve rested more. I don’t want to reopen your wounds.”

* * *

When Magnus awoke it was to a flushed siren straddling his waist, eyes spitting angry determination.

“Alec, what-”

“My wounds are nearly healed,” he started, fingers digging into the pillows near the pirate’s head. “I’m no longer weak and my strength has been returning. Tomorrow I might even be able to change back if I want to and this body has not stopped _aching_ since I woke up. I want you,” Alec growled, hips rolling into the human’s. “so take me.”

Magnus groaned, hands moving to his lover’s hips. “Get down here,” he demanded, tugging the siren down to steal his lips. Alec let out a eager sound at that, fingers pawing at the pants the pirate had gone to sleep in, impatience seeping through his veins.

“Magnus-” he tried, voice muffled against his lover’s plundering mouth. “I want-”

“I know what you want,” Magnus murmured, tugging the siren’s lower lip into his mouth and sucking slightly. “Be patient.”

Alec whined, hips rolling and dragging against his mate’s as he tugged restlessly at the sheets, letting out a soft pleased sound when Magnus rolled, placing the blue eyed male under his body. “Oh yes-”

The pirate chuckled, pulling back from his lover’s mouth to take in his flushed face. “Someone’s certainly eager.”

“Ever since I woke up this body has been aching and I cannot figure out how to get it to go away!” Alec exclaimed, squirming under the other male. “I think you would be eager too!”

Magnus blinked, letting his gaze wander down the siren’s body, a slow smirk stealing his mouth as he came to a stop on his weeping arousal. “You mean this?” He chuckled, wrapping long fingers around the heated flesh and pumping firmly.

Alec let out a strangled cry, back arching sharply as his head snapped back. “Oh gods-” He gasped, writhing when a thumb rubbed over the tip. “M-Magnus-”

“You’re sensitive,” he mused, eyes dark with lust.

“It’s-- _ahn_ \--my first time y-you idiot-” The siren gritted out, hips rolling desperately. “Of course I’m-- _ohh_ \--sensitive!”

Magnus chuckled, releasing his lover much to Alec’s protest, a sharp whine leaving his mouth. “You said you wanted me to take you,” he reminded, trailing kisses down the smaller male’s chest.

Alec moaned, eyes fluttering shut as he pressed up into the touch, letting his protests die out as Magnus nuzzled at the twin buds on his chest, mouth and fingers toying with the pebbled flesh until the siren was cursing, clawing at the sheets as his hips rocked against the pirate’s desperately, a flood of his lover’s name leaving his lips. “Magnus, Magnus, Magnus, _oh god, Magnus_!”

“Alec,” The pirate returned, voice husky with arousal as he moved lower, tongue tracing over the dips of his ribs.

He nearly screamed when Magnus’ mouth touched his arousal, body lurching upright only to crash back down onto the bed with a helpless cry, head thrashing from side to side as the pirate swallowed him down. “It’s- it’s t-too much, Magnus-” Alec gasped, tears filling his eyes at the rush of new sensations. “It’s-- _please!_ \--t-too much!”

The pirate took mercy, lifting his head to take in his lover’s face, face nearly matching the predatory look the siren sometimes wore. “Look at me,” he ordered, pushing the other male’s thighs wider as he reached for the oil kept in the drawer next to the bed. Alec obeyed with a soft whine, dazed eyes finding Magnus’ as he panted, cheeks flushed and lips swollen. Magnus smiled. “I’m going to prep you,” he murmured, uncapping the vial and pouring the liquid over his fingers, rubbing at the puckered skin behind Alec’s balls. “and then I’m going to take you.” He promised, pushing a finger into that tight heat and sending a strangled cry from the siren’s lips. “You’re mine, Alec. All mine.”

Alec nodded desperately, eyes squeezing shut as his brows furrowed at the feeling, hips twitching restlessly. “Magnus-”

“Shhh,” he soothed, pressing a kiss to his knee. “Just relax. Open up for me, darling.”

The siren gave a strangled moan, trembling as he peered up at the ceiling dazedly, struggling to take slow breaths. He wanted this, wanted it desperately, had for weeks now, and he wanted it _now_.

“That’s it,” Magnus praised, smiling crookedly as he pushed a second finger in with the first, pushing and stroking at velvet walls as he searched for that one spot-

“Holy _fuck_!” Alec shouted, eyes opening wide as he writhed, sparks of pleasure ricocheting up his spine. “Wha-what-”

He smirked, pursuing that spot and and sending his lover into another fit of overstimulation.

“Oh god, oh god, oh god-” Alec chanted, hips canting up as he thrashed, brain short-circuiting under the sudden onslaught of pleasure, muscles spasming.

Magnus chuckled, pressing a third finger in with ease as he watched his lover, a hand keeping Alec’s thighs open while he thrashed. When the siren showed no signs of even noticing, let alone discomfort, he dared to push a fourth finger into his lover’s heat, stretching his walls gingerly and drizzling more oil in around his fingers. The better stretched he was, the easier this would go, and while he didn’t want to hurt Alec he knew that there would at least be _some_ discomfort.

By the time he deemed the siren as ready as he’d ever be, stretching his entrance as much as he could without putting the rest of his hand in, Alec was a mess of tears and saliva, body vibrating with need and nearly on that edge.

“You’re beautiful,” Magnus breathed, sliding up his lover’s body as he slicked his arousal, guiding the head to the siren’s entrance. “Are you ready?”

Alec moaned breathlessly, blinking up at the pirate dazedly before he nodded shakily, winding his arms around Magnus’ neck. “Do it,” he breathed, voice hoarse from his cries.

Magnus hummed, stealing his lover’s mouth in a possessive kiss as he pressed his hips forward, earning a muffled cry. He went slow, moving in slow, drawn out thrusts and doing his best to distract from the pain that his lover was feeling. “I love you,” he breathed, pressing fluttering kisses to Alec’s face as his thumb stroked the siren’s knee.

“I love you too,” Alec panted, brows drawn as he bit at his lip, tugging slightly at Magnus’ hair as his hips hit his lover’s thighs.

“Alright?” He murmured, resting his forehead against the other male’s.

Alec nodded shakily, shifting under him with a small hiss of discomfort. It wasn’t an overwhelming pain--more of a slow burn than a sharp slice--but it was enough to ache, enough to make the siren pause. “I’m okay.” He breathed, peering up at his lover. “You can move.”

Magnus searched blue eyes for any hint of a lie, taking a deep breath when he found nothing but honesty before bringing his hips back no more than a couple inches and sinking back into his lover’s heat ever so slowly. It was torture of the best kind and Magnus would do it as long as Alec needed.

The siren let out a soft moan, a twinge of discomfort sliding up his spine before he rocked his hips down, ignoring it in an effort to get back that overwhelming pleasure. “More,” he breathed, mouthing at the human’s throat. “Please Magnus, more.”

The pirate groaned, fingers digging into the mattress as he drew back obediently, movements faster than before as he angled himself towards his lover’s prostate, chuckling slightly when Alec shouted out at his success.

“More!” He demanded, clutching at Magnus’ hair as he shuddered, arousal hot and aching between their bodies.

“So greedy,” Magnus teased, brushing his lips against the siren’s as he drew back almost all the way, jerking his hips forward and sending another wave of pleasure through the other male. He didn’t wait for any more urgings, beginning to set a steady pace that had both of them shivering in pleasure, that edge drawing steadily closer.

“M-Magnus!” Alec panted, back arched as his eyes rolled into the back of his head. “Y-yes- more-”

“Alec,” The pirate moaned, sliding a hand down between their bodies and grasping his lover’s arousal. Their mouths met in a mess of hungry tongues and swollen lips, cries of pleasure swallowed as Magnus brought them to the edge of that cliff.

“Oh god!” Alec cried, tears slipping down his cheeks at the pirate’s relentless pace, something building in his stomach, tightening his muscles and sending his body twitching. “Magnus, I don’t-”

“I love you,” he breathed, trailing hot kisses down the other male’s neck and creating the marks that Alec so loved to put on him.

“Love you too,” the siren nearly sobbed, trembling under his lover as he slid a hand down to clutch at the sheets, struggling to find something to ground himself with among the sea of pleasure lest he drown.

Magnus twisted his hand, swiping a thumb over the weeping tip of Alec’s arousal as he ground his hips, dragging his own against the spot that had his lover coming so beautifully undone.

A scream, loaded with power and holding something akin to the seductive songs he sometimes sung to Magnus escaped his mouth as he shuddered out his release, the sound sending the pirate right over the edge after him with little control. They shook, the warmth of Alec’s release hitting their chests as Magnus’ hips bucked, his own seed spilling deep inside his lover. The human slumped forward, catching himself on his elbows before he could crush the siren as Alec’s legs fell lax against the bed, a hand curled into his hair weakly as he panted, watery eyes clenched shut.

“Alec,” Magnus murmured, stroking his cheek. “Look at me, my love.”

Blue eyes opened slowly at that, dazed and sated.

“You’re safe now,” he murmured, pressing a kiss to his lover’s mouth and resting his forehead against the other male’s as he repeated Alec’s words. He closed his eyes as he let his own tears fall. “No one’s going to hurt you like that again.”

Alec nodded shakily, tightening his hold on the pirate. “Love you,” he finally whispered, cradling the human close as he cried.

Magnus smiled, stealing one last kiss. “I love you too.”


	6. Because Forever Starts With Goodbye

**Summary for the Chapter:**

> He knew they couldn’t do this forever, and this just made him face that terrible truth that much faster. He didn’t want to say goodbye but he didn’t know what else they could do. They were different…
> 
> God. Why did that have to matter?

**Notes for the Chapter:**

> It's not what you think.  
> Also  
> I'm not sorry ;_;

“Are they going to attack you when you change back?” Magnus questioned worriedly, watching as the siren shed his clothes.

Alec shook his head. “We’re far enough away from their home, they won’t bother me as long as I don’t stick around. They made it clear what would happen if I do.”

The pirate grimaced, taking the discarded cloth from his lover. “Where are you going to go?”

He smiled, leaning up to steal a kiss. “Where ever you go, of course. It’s no different from when you were sailing.”

“But won’t it bother you? Not having an actual home?”

Alec frowned, tilting his head to the side as he twined his fingers with his lover’s. “I can find a new home, besides… I think, that I wouldn’t want a new one if I couldn’t have you there with me.” He flushed slightly at that, looking away.

Magnus’ eyes softened. “Are you sure that you want to return already? You could join a crew with me and try out being human for a little while.”

He shook his head, turning to the ocean with a longing look. “I already miss it, I don’t think I could stand being trapped on a floating piece of wood with a bunch of stupid humans while the water was just in reach. I’d end up jumping in and giving myself away.”

Magnus sighed, eyes regretful. “I know.”

* * *

“Swim with me?” Alec requested, holding out a webbed hand as he gave the pirate a shy smile.

Magnus smiled back, taking the siren’s hand and letting himself be led into deeper water, unafraid when his head went under, his body pulled to deeper water. “Where are we going?” He questioned curiously, reaching out to brush his fingers against a colorful fish.

“I want to show you something,” Alec answered, swimming strongly, easily moving both of them through the water.

“And what would that something be?” Magnus teased, gazing up at his lover.

The siren huffed, swiping lightly at the human’s head. “It’s a surprise.”

* * *

“What is that?” Magnus breathed, eyes taking in the circle of colored rocks, their surface mottled with black and white. There were four of them placed around a large smooth stone that looked almost like an alter. Plant life bloomed around the scene, brushing against Magnus’ legs as they moved towards the rocks, stopping once they rested on the middle’s surface.

“This is where my brothers and sisters do rituals. There are hundreds of them all over, you just have to know where to look.” Alec explained, running a hand over the smooth surface they sat on.

Magnus nodded, moving to look closer at the colored rocks, blinking in surprise when he found that what he thought was simply coloring was actually symbols, the carefully drawn runes overlapping the white rock. “What kind of rituals?”

There was a silence and the pirate turned to gaze questioningly at the uncomfortable looking siren.

“I…” Alec bit his lip, eyes downcast as he toyed with his hands, tail flicking nervously.

“What is it?” Magnus frowned, moving back to his lover and tipping his chin up.

“I can… I can make you like me.” The siren breathed, the words spilling from his mouth in a flood. “You could stay, you wouldn’t have to leave unless you wanted to. You could live with the ocean like you’ve always wanted and I… you could stay with me.”

“Alec…” He shook his head, eyes wide in shock as he took in the rocks in a new light. “I didn’t know that that was even possible.”

“It’s a heavily guarded secret,” Alec mumbled, peering up at his lover hesitantly.

“What…” he took a deep breath, staring into those hopeful blue eyes. “What would we have to do?”

The siren’s face brightened, hands moving to clutch at Magnus’. “I have to claim you and mark you as mine, as the ocean’s. It will… it will hurt,” he warned, clinging to his lover’s touch as if he would slip away.

“That’s alright,” Magnus murmured, lifting a hand to brush his thumb against Alec’s bottom lip. “Are we doing it now?”

He shook his head. “It has to be when the moon is full. That’s when the ocean, and me, is at it’s strongest.”

“Three days,” the pirate murmured.

* * *

He does not say goodbye to anything but the island that they had claimed as their own. He has no one to say goodbye too and even if he did, he isn’t certain that he’d be able to tell them that he was probably never coming back.

Instead he sits on the sand, gazing out at the water as he awaits his lover, body as prepped and ready as he could make it.

They don’t speak, other than to say ‘I love you’ as Alec brings them back to the circle of rocks. The scene is bathed in moonlight now, the rock that he’s laid on a pale white that turns his tanned skin a light brown. He doesn’t really know what this entails, other than than claiming, doesn’t know if when Alec said it would hurt if he meant the slide of the siren’s arousal into his entrance or if something else is meant to happen but he’s ready.

His breath escapes him when his lover seats himself inside of his body for the first time, legs pushed up over Alec’s shoulders as his tail flicks, keeping them together and sending his hips rocking in slow thrusts. Magnus thinks he understands why so many of his kind prefer to do this on land.

It is not painless. And although he prepped himself with the last of the oil there is only so much one can do when they’ve gone so long without penetration. It is not overly painful either. It is an ache, a pressure that he is all too willing to stand if it means that he can stay with Alec forever.

Their bodies move together in the water, bathed in moonlight. There is a power that Magnus can feel in the water, in the rock he lies on, in Alec as he hovers over him and, he realizes, in him. With their coupling is something else, something that both wounds and heals, that both hurts and pleasures, that both pressures and eases.

Magnus drowns in it.

Alec’s thrusts are harder now, tail stirring up the water as he moves in and out of the pirate, eyes glazed with pleasure and yet never once leaving his lover’s face. He seems to be looking for something, waiting for something, and as Magnus comes he seems to find it.

There’s a shiver in the air as the pirate gasps for breath that he can no longer seem to find, the water flooding through his lungs bringing a horrifying shock through his body after the pleasure, his limbs weak as he lifts hands to clutch at his throat, mouth moving uselessly as he chokes and spasms, lungs rejecting the water that had been perfectly breathable just moments before. Alec’s hands find his, pulling them away from his body gently as he continues to thrust, finding his own release as Magnus’ lungs fill. This time he’s drowning for real.

He doesn’t know if those are tears in Alec’s eyes, spilling from agonized blue but there are certainly tears in his. His head is oh so heavy, body ceasing its struggle when his desperate gasps get him nothing but more water, the oxygen he so needs too far out of reach.

“I love you,” he thinks he hears Alec say, a brush of lips meeting his own.

Magnus thinks that he might say _‘I love you’_ back, thinks that he might have added _‘how could you?’ ‘I trusted you’_ and _‘I forgive you’_.

He takes one last desperate breath and closes his eyes.

His chest moves no more.

* * *

Alec does not know how long he lays there, weeping over his love as the moon shines down on them, her rays gentle in their illumination of his pain, powering the runes that mark the rocks around them.The black marks glow white in the water, power thrumming over the stone Magnus rests on.

His skin is changing, brilliant reds and deep purples spreading out over his legs as scales rise to the surface. His legs fuse together, forming a long and beautiful tail that ends in a set of stunning black fins that take Alec’s breath away. Ebony feathers grow around his waist, fading into tanned skin as gills form just beneath his ears which grow fins akin to the other siren’s, his a shade of crimson.

Swirls of violet and ebony travel up around his wrists and follow the spines down his back, turning Magnus’ skin into a riot of color and beauty that has Alec crying all the harder.

His skin is cold when the other male touches him, a lukewarm that is so different from the hot temperatures the siren had grown used to. He reminds himself that Magnus wanted this too.

“Magnus,” he whispers, cradling his lover close. “Please wake up… I love you, please…”

The first breath nearly sends a sob of relief from his lips, tail wrapping around the other male’s as he basked in the relief that everything would be okay.

And as Magnus opened his eyes, he was reborn.

**Notes for the Chapter:**

> Who thought that I would actually kill Magnus off? *raises hand* ._.  
> I honestly did not know what the fuck I was gonna do to make him into a siren so when the drowning part came up I was like oh shit. I’ll admit, I briefly entertained the idea of sending him to his death in more ways than one but this is a birthday present so it had to be happy. The things I do for people.  
> Anyways~  
> I hope it was at least somewhat enjoyable. The second part of her gift will be up tomorrow so look for that if you so wish and thanks for reading~


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